feat(frontend): use the Sifi API for getting token balances

[boriskubrik]

• Replace the multicall to get the token balances with using the API provided by Sifi.
• Store all balanceMaps in state, using the chainId as a key. We fetch once and get the balances for all tokens.
• Stale time is set to 1 minute. The refetching logic remains the same, handled by the useRefetchBalances hook.
• isLoading is stored in state. CoinSelector does not yet support it for the balances, this needs to be added to shared-ui.
• Once we have the the loading state, we can move the first fetch to when the user has opened the TokenSelector. For now, it would look bad to show the UI without any balances.
• Displaying 0 for coins without balances. Not displaying anything while we are fetching the balances. This should be replaced with the loading state.

[immutablegoblin]

I also can't work out whats going on here but something isn't right:

When I switch to Avalance we're trying to run balanceOf on this contract, but it's not a token, so it returns 0x and fails, spamming the console again - is this one of ours? Doesn't look like it from the multichain activity as far as I can tell.

https://etherscan.io/address/0x2791bca1f2de4661ed88a30c99a7a9449aa84174#multichain-portfolio

My understanding is we're only supposed to be running balanceOf directly on the currently selected to and from tokens for the most up to date balance, so this seems unexpected.

[immutablegoblin]

Oh I think I worked it out.

Currently if you change networks it will take the previously selected token and then try and fetch the balance for the old token address on the new network resulting in a failure.

This can probably be fixed separately, I don't think it's caused by the changes here.

[boriskubrik]

@immutablegoblin I've suppressed the Coingecko errors. e3bd912

We still see 500 (Internal Server Error)s from the SDK, but it is a separate matter.